Seems like n=11 should have been n=1. Use 19, 21, and 1 as a numerator of /41 and you end up with all the same percentages written in the abstract. A typo that should have been caught, but surely nothing more than that and certainly not substantive enough to qualify the claim below:
> This paper is very bad. The numbers in the abstract don’t even add up, which any reviewer should have caught.